### Bioenergetics: The Proton-Motive Force in Mitochondria #### Question 31:In this question, we explore the mechanisms by which the proton-motive force is generated within the mitochondria, a crucial aspect of cellular respiration and energy production.#### Question:**In the mitochondria, a proton-motive force is generated by the:**1. **Reduction of NAD⁺ by the first electron carrier in the electron transport chain.**2. **Flow of protons through ATP synthase down their concentration gradient.**3. **Pumping of hydrogen ions from the mitochondrial matrix across the inner membrane and into the intermembrane space.**4. **Lowering of pH in the mitochondrial matrix.**### Explanation:- **Reduction of NAD⁺:** This initial step involves the acceptance of electrons by NAD⁺, forming NADH, but does not directly generate the proton-motive force. - **Flow of Protons through ATP Synthase:** This process is crucial for ATP synthesis, but it is a result of the proton-motive force rather than the cause of its generation. - **Pumping of Hydrogen Ions:** The correct answer. This process creates a proton gradient by transporting H⁺ ions from the mitochondrial matrix into the intermembrane space, leading to a higher concentration of protons in the intermembrane space compared to the matrix. - **Lowering of pH in the Mitochondrial Matrix:** This would be a consequence of proton pumping, which increases the concentration of H⁺ ions in the intermembrane space, thus lowering the pH when protons flow back through ATP synthase.This question emphasizes the importance of understanding the electron transport chain and chemiosmosis in the context of bioenergetics. The generation of the proton-motive force is an integral part of how cells produce energy in the form of ATP.

Name: ### Bioenergetics: The Proton-Motive Force in Mitochondria #### Quest
Uploaded: 2024-03-20T06:42:55.000Z
Channel: Bartleby
Description: ### Bioenergetics: The Proton-Motive Force in Mitochondria #### Question 31:In this question, we explore the mechanisms by which the proton-motive force is generated within the mitochondria, a crucial aspect of cellular respiration and energy produc